The present invention relates generally to the field of LEEP or Loop Electrosurgical Excision Procedures, and in particular to a new and useful guard and guide for such procedures and other procedures involving the use of a probe handle.
The American Cancer Society estimates 11,270 new cases of cervical cancer in the United States in 2009, with 4,070 deaths from the disease (1). Most cervical cancer can be prevented. Widespread screening of cervical cytology with the Papanicolaou smear (Pap smear) allows early identification of pre-invasive lesions and the ability to triage patients for further evaluation. In this procedure a sample of cells is collected from the cervix and spread on a slide for cytological evaluation. Current American College of Obstetricians and Gynecologists (ACOG) guidelines recommend initiating cervical cancer screening at age 21 years with a Pap smear and continuing every two years till age 29 (2). Women aged 30 years and older without risk factors may extend the interval to every three years (2). Fifty to sixty million women in the United States have a Pap smear each year. Three to five million women in the United States have an abnormal result.
The Bethesda System for reporting the results of cervical cytology was developed as a uniform system of terminology that would provide clear guidance for clinical management (3). The nomenclature consists of “negative for intraepithelial lesion or malignancy” for slides with no cytological evidence of neoplasia. Alternatively slides with abnormalities are categorized into “atypical squamous cells (ASC), atypical glandular cells (AGC), low grade squamous intraepithelial lesions (LSIL), high grade squamous intraepithelial lesions (HSIL) or squamous carcinoma.” Each patient with slides displaying cytologic abnormalities must be evaluated by the care provider for subsequent management and further workup. The American Society for Colposcopy and Cervical Evaluation (ASCCP) provides guidelines for management of cytologic cervical abnormalities (4). As cytology is typically reflective of a cellular process not visible to the naked eye, further evaluation is often recommended with colposcopy. Colposcopy is a medical diagnostic procedure that offers an illuminated magnified view of the cervix and tissues of the vagina and vulva. Pre-invasive lesions are visually distinguished by specific characteristics by a trained colposcopist. Abnormalities are highlighted by the application of acetic acid and/or Lugols solution. The colposcopist obtains biopsies of any abnormal areas for histologic confirmation prior to any treatment intervention.
Histologic classification is a two tiered system that designates CIN (cervical intraepithelial neoplasia) 1 as referring to low grade lesions and CIN 2, 3 to high grade precursors (5). ASCCP provides guidelines for the management and treatment of these histologic lesions (5). Depending on the exact diagnosis and clinical context, recommended treatment may be either excision or ablation, or excision alone. Excisional methods that provide a tissue specimen for pathologic review include cold knife conization, laser conization, electrosurgical needle conization or loop electrosurgical excision procedures (LEEP).
To practice LEEP procedure, first an insulated bivalve speculum is placed in the vagina and the cervix is isolated. Then the diseased cells are identified with specific solutions. Once highlighted (FIGS. 1 and 2), the cellular pathology is excised using an a thin low voltage electrified wire loop shown in FIG. 3. In cutting mode the high frequency current is produced in a smooth uninterrupted sine wave. As the loop is applied to the cervical tissue an arc occurs near the point of contact and the cells rapidly heat and explode into steam. The steam envelope allows for continued arcing, extending the cut with little coagulation artifact. In coagulation mode tissue is fulgurated with shorts bursts of high peak voltage current. Typically both modalities are combined in a blend mode. The procedure lends itself to ease of use in an office setting. Local anesthesia is typically administered, although in certain situations a more monitored operative setting with general anesthesia may be preferred.
A variety of wire loops are available to choose from in order to tailor the specimen to the anatomy of the patient and the characteristics of the lesion. A loop should be chosen that allows excision of the transformation zone to an adequate depth without contact to the vaginal side wall. The loop is attached to a pencil like base that is controlled with a foot switch. Current is applied as the loop contacts the cervix and the specimen is excised. An additional endocervical specimen may be excised as necessary. The excision bed is then commonly fulgurated to reduce bleeding.
A recent analysis shows LEEP to be cost-effective (6). That together with ease of use accounts for its rising popularity in the United States. Women treated with loop excision are likely to convert to Human Papillomavirus (HPV) negative status, which eliminates the risk for H PV-related cervical dysplasia and cancer. The survival rate for properly treated early-stage cervical cancers is between 70 percent and 100 percent. Any device that simplifies the safe and effective use of LEEP in the office setting would have the potential for widespread use.